Republican members of Congress in swing states such as Florida (Rep. Cliff Stearns), Colorado (Rep. Mike Coffman) and Missouri (Rep. Vicky Hartzler) have publicly raised questions about Obama’s citizenship in recent weeks.

In North Carolina, the state GOP convention will be headlined next week by Donald Trump, whose 2011 crusade to unearth details about Obama’s origins drew global attention and prompted the White House to release the president’s long-form birth certificate.

The Romney campaign has since leveraged Trump as a campaign surrogate and fund-raiser.

Also in North Carolina, a state both campaigns are aggressively targeting, The Charlotte Observer recently retracted its endorsement of a Republican congressional candidate after he said he was “suspicious” of Obama’s birth certificate.